WO2016079811A1 - Wear-resistant component and production method for same - Google Patents

Wear-resistant component and production method for same Download PDF

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Publication number
WO2016079811A1
WO2016079811A1 PCT/JP2014/080538 JP2014080538W WO2016079811A1 WO 2016079811 A1 WO2016079811 A1 WO 2016079811A1 JP 2014080538 W JP2014080538 W JP 2014080538W WO 2016079811 A1 WO2016079811 A1 WO 2016079811A1
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WO
WIPO (PCT)
Prior art keywords
layer
build
region
wear
built
Prior art date
Application number
PCT/JP2014/080538
Other languages
French (fr)
Japanese (ja)
Inventor
真之 大石
天野　昌春
Original Assignee
株式会社小松製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社小松製作所 filed Critical 株式会社小松製作所
Priority to US15/500,689 priority Critical patent/US10500666B2/en
Priority to PCT/JP2014/080538 priority patent/WO2016079811A1/en
Priority to DE112014007181.1T priority patent/DE112014007181T5/en
Priority to AU2014411634A priority patent/AU2014411634B2/en
Priority to CN201480081868.7A priority patent/CN106715022B/en
Priority to JP2016559728A priority patent/JP6538072B2/en
Publication of WO2016079811A1 publication Critical patent/WO2016079811A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/04—Welding for other purposes than joining, e.g. built-up welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
    • B23K31/02—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to soldering or welding
    • B23K31/025—Connecting cutting edges or the like to tools; Attaching reinforcements to workpieces, e.g. wear-resisting zones to tableware
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/24—Features related to electrodes
    • B23K9/28—Supporting devices for electrodes
    • B23K9/29—Supporting devices adapted for making use of shielding means
    • B23K9/291—Supporting devices adapted for making use of shielding means the shielding means being a gas
    • B23K9/295—Supporting devices adapted for making use of shielding means the shielding means being a gas using consumable electrode-wire

Definitions

  • Wear-resistant parts such as ripper and tooth are used as parts constituting work machines that operate in the presence of earth and sand, such as hydraulic excavators, bulldozers, and wheel loaders.
  • An overlay layer may be formed in a region where particularly high wear resistance is required in the wear-resistant component.
  • As the build-up layer for example, a material in which hard particles are dispersed in a base material made of steel can be used.
  • the build-up layer can be formed by, for example, build-up welding (see, for example, Japanese Patent Laid-Open No. 2008-763 (Patent Document 1) and Japanese Patent Laid-Open No. 8-47774 (Patent Document 2)).
  • a wear-resistant part having a build-up layer is obtained by preparing a base part molded in a desired shape and forming the build-up layer so as to cover an area of the base part that requires particularly high wear resistance. It is done. While the build-up layer can improve the durability of the wear-resistant component, there may be a demerit caused by the formed build-up layer. For example, when a build-up layer is formed on the tooth of a bucket of a hydraulic excavator, the penetration resistance of the tooth into the earth and sand may increase.
  • An object of the present invention is to suppress demerits caused by the formation of a built-up layer in a wear-resistant part having a built-up layer.
  • a wear-resistant component according to the present invention includes a base portion made of a first metal and a built-up layer disposed in contact with the base portion so as to cover a covering region that is a part of the surface of the base portion. .
  • the exposed region and the surface of the built-up layer form a forged surface that forms the same surface. .
  • the overlay layer is formed on the surface of the base portion by a technique such as overlay welding.
  • a technique such as overlay welding.
  • a step is formed between the surface of the overlay layer and the exposed region of the base portion. This level
  • step difference becomes a cause of the demerit resulting from formation of the overlaying layer.
  • a built-up layer may be formed on the tooth of a bucket of a hydraulic excavator.
  • the penetration resistance of the tooth with respect to the earth and sand may be increased due to the formation of the step.
  • a built-up layer is formed on a component that is used while being in contact with another component, a desired contact state with the other component may not be sufficiently achieved due to the step.
  • the exposed area of the base part and the surface of the built-up layer form the same surface at the built-up end. Therefore, the demerit by formation of the build-up layer resulting from the said level
  • the built-up end portion in the forged surface it is possible to omit the step of processing so that the exposed region of the base portion and the surface of the built-up layer are flush with each other by cutting or the like. Therefore, processing of the built-up end portion having a large hardness difference and processing of the built-up layer having high hardness can be avoided.
  • the wear-resistant component of the present invention it is possible to provide a wear-resistant component capable of suppressing the disadvantages caused by the formation of the build-up layer in the wear-resistant component having the build-up layer.
  • the build-up layer may include a parent phase made of the second metal and hard particles dispersed in the parent phase.
  • the hard particles located in the surface layer region of the built-up layer that is within the average particle diameter of the hard particles from the surface of the built-up layer are arranged side by side in a state embedded in the built-up layer. May be. By doing in this way, it is suppressed that a hard particle protrudes greatly from the surface of the build-up layer. As a result, falling off of the hard particles during use of the wear resistant part is suppressed.
  • the average particle diameter of the hard particles can be obtained by observing a cross section perpendicular to the surface of the build-up layer with an optical microscope, and calculating the average value of the diameters of 10 observed hard particles.
  • the hard particles located in the surface layer region of the build-up layer may be arranged so as to contact the surface of the build-up layer. Thereby, the area
  • a central angle corresponding to a region exposed from the surface of the buildup layer of the hard particles located in the surface layer region of the buildup layer may be an acute angle (less than 90 °).
  • the build-up layer may include a protruding portion that protrudes toward the base portion in a region including an interface between the build-up layer and the base portion. Thereby, it is suppressed that a build-up layer peels from a base part.
  • At least a part of the hard particles may enter the protruding portion. Thereby, it is suppressed more reliably that a build-up layer peels from a base part.
  • the method of manufacturing a wear-resistant component according to the present invention includes a step of preparing a base member made of a first metal, and overlaying so as to cover and cover the coating region that is a part of the surface of the base member.
  • the base member on which the build-up layer is formed so that the build-up end portion that is the boundary between the step of forming the layer and the exposed region that is the region other than the cover region on the surface of the base portion is processed Forging.
  • the base member on which the build-up layer is formed is forged so that the build-up end portion is processed. Therefore, wear-resistant parts that are forged surfaces in which the surface of the built-up layer and the exposed region of the base portion constitute the same surface are manufactured at the built-up end, and there are disadvantages due to the formation of the built-up layer due to the above steps. It is suppressed.
  • the built-up end portion in the forged surface it is possible to omit the step of processing so that the exposed region of the base portion and the surface of the built-up layer are flush with each other by cutting or the like.
  • a wear-resistant component of the present invention it is possible to manufacture a wear-resistant component capable of suppressing the disadvantages caused by the formation of the build-up layer in the wear-resistant component having the build-up layer. it can.
  • the base member on which the overlay layer is formed may be hot forged.
  • hot forging it becomes possible to easily forge the base member on which the build-up layer is formed.
  • a build-up layer including a parent phase made of the second metal and hard particles dispersed in the parent phase may be formed.
  • the wear-resistant component and the manufacturing method thereof of the present invention it is possible to suppress demerits caused by the formation of the build-up layer in the wear-resistant component having the build-up layer.
  • FIG. 3 is a schematic sectional view showing a section taken along line III-III in FIG. 2.
  • FIG. 1 is a schematic perspective view showing the structure of a bucket of a hydraulic excavator.
  • FIG. 2 is a schematic plan view showing the structure of the tooth.
  • 3 is a schematic cross-sectional view showing a cross section taken along line III-III in FIG.
  • bucket 1 is attached to the tip of a hydraulic excavator arm (not shown) to excavate earth and sand.
  • the bucket 1 is composed of a plate-like member, and a plurality of (shown in FIG. 1) attached to the main body 10 such that a main body 10 having an opening and a part of the main body 10 project from the excavation side of the outer periphery 12 of the opening
  • the bucket 1 includes three) teeth 20 and a mounting portion 30 disposed on the main body 10 on the side opposite to the side on which the teeth 20 are attached.
  • Bucket 1 is supported by an arm of a hydraulic excavator at mounting portion 30.
  • the tooth 20 is required to have high wear resistance (earth and sand wear resistance).
  • the tooth 20 is an earth and sand wear resistant part that is a machine part used for an application in contact with earth and sand.
  • the tooth 20 includes a distal end 21 and a proximal end 22, as shown in FIG.
  • the tooth 20 is attached to the main body 10 on the proximal end 22 side, and the distal end 21 side protrudes from the opening outer peripheral portion 12 of the bucket 1.
  • the tooth 20 is used while being in contact with the main body 10 which is another part.
  • the bucket 1 enters the earth and sand from the tip 21 side of the tooth 20. Therefore, particularly high wear resistance (earth and sand wear resistance) is required on the tip 21 side of the tooth 20.
  • the tooth 20 is built up in contact with the base portion 25 so as to cover the base portion 25 made of the first metal and the covering region 25 ⁇ / b> A which is a part of the surface of the base portion 25.
  • Layer 27 As the first metal constituting the base portion 25, for example, carbon steel for machine structure or alloy steel for machine structure (for example, S45C, SCM435, SMn steel, SCr steel containing an equivalent amount of carbon, SCM steel etc.) can be employed.
  • the built-up end portion 29 that is the boundary between the covered region 25A and the exposed region 25B that is a region other than the covered region 25A on the surface of the base portion 25, the exposed region 25B and the surface 27A of the built-up layer 27 are flush with each other. It is a forged surface to constitute.
  • the surface 27A of the overlay layer 27 is a forged surface over the entire area.
  • FIG. 4 is a schematic cross-sectional view showing the structure of a tooth of a comparative example having a built-up layer.
  • the built-up layer is formed on a steel base portion having a desired shape.
  • a comparative tooth 920 that is a general tooth having a built-up layer includes a distal end 921 and a proximal end 922.
  • a built-up layer 927 is formed on the tip 921 side of the tooth 920.
  • the overlay layer 927 is formed, for example, by overlay welding so as to cover the covering region 925A of the base portion 925 formed in a desired shape.
  • the exposed region 25 ⁇ / b> B and the surface 27 ⁇ / b> A of the built-up layer 27 form the same surface at the built-up end 29, thereby It is possible to avoid an increase in penetration resistance due to a step in the case.
  • the built-up end portion 29 in the forged surface it is possible to omit the step of processing so that the exposed region 25B and the surface 27A of the built-up layer 27 are flush with each other by cutting or the like. Therefore, the processing of the built-up end portion 29 having a large hardness difference and the processing of the built-up layer 27 having a high hardness can be avoided.
  • the demerit resulting from formation of the build-up layer 27 can be suppressed. Further, after forming a built-up layer on the base member, forging is performed to form a region including the tip 21, and the region including the tip 21 is covered with the built-up layer 27 as shown in FIG. Thus, the tooth 20 having high wear resistance can be obtained.
  • FIG. 5 is a schematic cross-sectional view showing a structure near the surface of the overlay layer.
  • FIG. 6 is a schematic cross-sectional view showing a structure near the interface between the build-up layer and the base portion.
  • build-up layer 27 includes a mother phase 95 made of a second metal and hard particles 91 dispersed in mother phase 95.
  • the second metal constituting the parent phase 95 can be, for example, a mixture of a metal derived from a welding wire and a first metal constituting the base portion 25.
  • the hard particles 91 particles having a hardness higher than that of the parent phase 95, for example, particles made of a cemented carbide can be used.
  • the build-up layer 27 has higher wear resistance (earth and sand wear resistance) than the base portion 25.
  • the surface 27A of the built-up layer 27 is a forged surface.
  • the hard particles 91 located in the built-up layer surface layer region 27 ⁇ / b> B, which is a region within the average particle diameter of the hard particles 91 from the surface 27 ⁇ / b> A of the built-up layer 27, are arranged side by side while being embedded in the built-up layer 27. . Thereby, it is suppressed that the hard particles 91 are greatly protruded from the surface 27 ⁇ / b> A of the built-up layer 27. As a result, falling off of the hard particles 91 during use of the tooth 20 is suppressed, and the wear resistance of the tooth 20 is improved.
  • the hard particles 91 located in the build-up layer surface layer region 27B may be arranged so as to be in contact with the surface 27A of the build-up layer 27 as shown in FIG. Thereby, the area
  • the central angle ⁇ corresponding to the region of the hard particles 91 exposed from the surface 27A of the built-up layer 27 is preferably an acute angle (less than 90 °). Thereby, the area
  • build-up layer 27 includes a protruding portion 99 that protrudes toward base portion 25 in a region including the interface between build-up layer 27 and base portion 25. Due to the anchor effect by the protruding portion 99, the build-up layer 27 is prevented from peeling from the base portion 25. At least a part of the hard particles 91 enters the protruding portion 99. Thereby, peeling of the build-up layer 27 from the base part 25 is suppressed more reliably. Between the hard particles 91 entering the projecting portion 99 and the base portion 25, the parent phase 95 of the built-up layer 27 is interposed. The hard particles 91 entering the protruding portion 99 and the base portion 25 are not in contact with each other.
  • the center of the hard particle 91 is located outside the protrusion 99 (a region that is less than 1 ⁇ 2 of the volume of the hard particle 91 enters the protrusion 99).
  • One hard particle 91 enters each protrusion 99.
  • the depth of each protrusion 99 is smaller than the radius of the hard particles 91 entering the protrusion 99.
  • FIG. 7 is a flowchart showing an outline of a tooth manufacturing method.
  • 8 and 9 are schematic cross-sectional views for explaining the manufacturing method of the tooth.
  • FIG. 10 is a schematic cross-sectional view for explaining a method for forming the build-up layer.
  • a base member preparation step is first performed as a step (S10).
  • a base member 50 to be the base portion 25 of the tooth 20 is prepared.
  • the base member 50 is made of a first metal.
  • the base member 50 has a cylindrical shape.
  • the base member 50 has a cylindrical shape including one end surface 52, the other end surface 53, and a side surface 51 connecting the one end surface 52 and the other end surface 53.
  • a first chamfered portion 52A is formed in a region where one end surface 52 and the side surface 51 are connected.
  • a second chamfered portion 53 ⁇ / b> A is formed in a region where the other end surface 53 and the side surface 51 are connected.
  • one end surface 52 side of the base member 50 corresponds to the distal end 21 side of the tooth 20, and the other end surface 53 side of the base member 50 corresponds to the proximal end 22 side of the tooth 20.
  • a build-up layer forming step is performed as a step (S20).
  • the meat is formed so as to cover the covering region 51A in contact with the covering region 51A which is a part of the surface of the base member 50 prepared in the step (S10).
  • a built-up layer 60 is formed.
  • the overlay layer 60 is formed so as to cover a desired region of the base portion 25 by performing hot forging described later.
  • the covering region 51A can be determined, for example, by performing a hot forging simulation using a finite element method in advance.
  • build-up layer 60 is formed so as to cover one end surface 52 side of side surface 51, first chamfered portion 52 ⁇ / b> A and one end surface 52.
  • the build-up layer 60 can be formed, for example, by build-up welding using a carbon dioxide arc welding method as follows.
  • the overlay layer forming apparatus includes a welding torch 70 and a hard particle supply nozzle 80.
  • the welding torch 70 includes a welding nozzle 71 having a hollow cylindrical shape, and a contact tip 72 disposed inside the welding nozzle 71 and connected to a power source (not shown). While contacting the contact tip 72, the welding wire 73 is continuously supplied to the distal end side of the welding nozzle 71.
  • the welding wire for example, JIS standard YGW12 can be adopted.
  • a gap between the welding nozzle 71 and the contact tip 72 is a shield gas flow path.
  • the shield gas flowing through the flow path is discharged from the tip of the welding nozzle 71.
  • the hard particle supply nozzle 80 has a hollow cylindrical shape. Hard particles 91 are supplied into the hard particle supply nozzle 80, and the hard particles 91 are discharged from the tip of the hard particle supply nozzle 80.
  • the built-up layer 60 can be formed by the following procedure using the built-up layer forming apparatus.
  • a voltage is applied between the base member 50 and the welding wire 73 using the base member 50 as one electrode and the welding wire 73 as the other electrode, an arc 74 is formed between the welding wire 73 and the base member 50. .
  • the arc 74 is cut off from the surrounding air by the shielding gas discharged along the arrow ⁇ from the tip of the welding nozzle 71.
  • the shielding gas for example, carbon dioxide can be employed.
  • Part of the base member 50 and the tip of the welding wire 73 are melted by the heat of the arc 74.
  • the droplet formed by melting the tip of the welding wire 73 moves to the molten region of the base member 50.
  • a molten pool 92 which is a liquid region in which the melted base member 50 and the welding wire 73 are mixed is formed.
  • Hard particles 91 discharged from the hard particle supply nozzle 80 are supplied to the molten pool 92
  • the molten pool 92 that has been solidified becomes a built-up layer 60.
  • the build-up layer 60 includes a mother phase 95 formed by solidifying the molten pool 92 and hard particles 91 dispersed in the mother phase 95.
  • the boundary between the covered region 51 ⁇ / b> A and the exposed region 51 ⁇ / b> B is the built-up end portion 59.
  • the build-up welding can be performed, for example, under the conditions of a welding current of 230 A, a welding voltage of 17 V, a hard particle supply amount of 110 g / min, and a bead surplus height of 4 mm.
  • JIS standard YGW11 may be adopted as the welding wire.
  • As the hard particles WC or W 2 C-based particles may be employed.
  • a hot forging process is performed as a process (S30).
  • the base member 50 on which the build-up layer 60 is formed in the step (S20) is hot forged.
  • the base member 50 on which the build-up layer 60 is formed is heated to a temperature at which hot forging is possible, and the inside of the mold having a cavity corresponding to the shape of the desired tooth 20 is obtained. Placed and forged.
  • the region of the base member 50 including the built-up end portion 59 is processed. Due to the hot forging, the built-up end portion 59 becomes the built-up end portion 29.
  • the tooth 20 in which the exposed region 25B and the surface 27A of the built-up layer 27 form the same surface in the built-up end portion 29 is obtained.
  • the exposed region 25B and the surface 27A of the built-up layer 27 are forged to form the same surface corresponding to the region where the built-up end portion 59 of the mold surface used in hot forging is processed. It becomes a surface.
  • the exposed region 25B and the surface 27A of the built-up layer 27 constitute the same surface corresponding to the shape of the forging die.
  • the built-up end portion 29 is included in the forged surface.
  • the hard particles 91 located in the built-up layer surface layer region 27B are arranged so as to contact the surface 27A of the built-up layer 27 (see FIG. 5).
  • the central angle ⁇ corresponding to the region exposed from the surface 27A of the built-up layer 27 of the hard particles 91 located in the built-up layer surface region 27B is an acute angle (less than 90 °).
  • the base member 50 on which the build-up layer 60 is formed is hot forged so that the vicinity of the interface between the build-up layer 60 and the base member 50 is formed when the build-up layer 60 is formed. Due to the influence of the hard particles 91 located in the protrusion 20, the protrusions 99 are formed in the overlay layer 27 in the tooth 20. At least a part of the hard particles 91 enters the protruding portion 99.
  • the surface layer region of the build-up layer 27 excellent in wear resistance in which the hard particles 91 are arranged so as to be in contact with the surface 27A, and the protrusion 99 that suppresses the peeling of the build-up layer 27 from the base portion 25; Are formed simultaneously.
  • a heat treatment step is performed as a next step (S40).
  • heat treatment is performed on the tooth 20 obtained by hot forging in the step (S30).
  • the heat treatment performed in the step (S40) is, for example, quenching and tempering. Thereby, desired hardness and toughness can be imparted to the base portion 25 of the tooth 20.
  • the tooth 20 in the present embodiment is completed by the above procedure.
  • the surface layer portion of the base member corresponding to the region of the base member where the build-up layer is to be formed is removed in advance.
  • the overlay layer may be formed after the undercut portion is formed on the base member.
  • the tooth 20 was produced in the same procedure as the manufacturing method described in the above embodiment, and the structure of the overlay layer and the like were confirmed, and an experiment was conducted to confirm the penetration resistance of the obtained tooth 20 into the clay ( Example).
  • the overlay layer forming step (step (S20)) was omitted, and a tooth was formed by depositing the overlay layer after heat treatment, and a similar experiment was performed (comparison) Example).
  • the molds used for hot forging have the same shape. The details of the experiment are as follows.
  • FIG. 11 is a photograph showing a cross section of the tooth 20 of the example.
  • the exposed region 25 ⁇ / b> B and the surface 27 ⁇ / b> A of the built-up layer 27 are forged surfaces that constitute the same surface. From this, it is confirmed that the tooth 20 in the said embodiment can be manufactured with the manufacturing method in the said embodiment. A crack is not seen between the build-up layer 27 and the base part 25, and the malfunction by having implemented hot forging after formation of the build-up layer is not confirmed.
  • FIG. 12 is an optical micrograph of the vicinity of the surface of the overlay layer of the example.
  • FIG. 13 is an optical micrograph of the vicinity of the surface of the overlay layer of the comparative example.
  • the hard particles 91 protrude greatly from the surface 27 ⁇ / b> A of the build-up layer.
  • FIG. 12 in the build-up layer of the example that has undergone processing by forging after formation of the build-up layer, hard particles 91 located in the surface layer region are embedded in the build-up layer (parent phase 95). Are arranged side by side.
  • the hard particles 91 are arranged in contact with the surface 27 ⁇ / b> A of the built-up layer 27.
  • the central angle ⁇ corresponding to the region of the hard particles 91 exposed from the surface 27A of the built-up layer 27 is an acute angle (less than 90 °). This is considered to be because when the build-up layer is processed by forging, the hard particles 91 protruding from the surface 27A of the build-up layer are pushed into the parent phase 95 having a relatively low hardness.
  • FIG. 14 is an optical micrograph of the vicinity of the interface between the build-up layer and the base portion of the example.
  • FIG. 15 is an optical micrograph of the vicinity of the interface between the overlay layer and the base portion of the comparative example.
  • the interface between the build-up layer (matrix phase 95) and the base portion 25 is It is in a flat state.
  • the build-up layer (matrix 95) was formed in a region including the interface between the build-up layer (matrix 95) and the base portion 25.
  • the protrusion 99 is considered to be formed by the influence of the hard particles 91 that existed in the vicinity of the interface with the base member when the build-up layer is processed by forging.
  • the hard particles 91 that have contributed to the formation of the protruding portion 99 are in a state in which at least a part thereof has entered the protruding portion 99.
  • FIG. 16 is a photograph of the appearance of the tooth of the example used for the penetration resistance test.
  • FIG. 17 is a photograph of the appearance of the tooth of the comparative example subjected to the penetration resistance test.
  • the surface of a tooth is in the flat state.
  • the build-up layer 27 exists so as to form a step on the surface of the tooth. is doing.
  • 16 and 17 were made to penetrate oil clay assuming earth and sand, and the penetration resistance at that time was measured.
  • the displacement speed of the tooth at the time of penetration was 1 mm / sec, and the tooth was penetrated into oil clay having a flat surface until the tip of the tooth reached a position where the depth was 50 mm.
  • FIG. 18 shows the results of the penetration resistance test.
  • the solid line corresponds to the test result of the example
  • the broken line corresponds to the test result of the comparative example.
  • the penetration resistance when the displacement of the tooth reaches 50 mm is about 0.25 kN in the comparative example, and is about 0.21 kN in the example.
  • the penetration resistance of the example is reduced by about 15% compared to the comparative example.
  • the tooth of the bucket of the working machine has been described as an example of the wear-resistant part of the present invention.
  • the wear-resistant part of the present invention is not limited to this, for example, the crawler belt of the work machine. It can be applied to components such as rollers, bushes, links, shoes, idlers and sprockets (sprocket teeth) constituting the undercarriage, and teeth of a crushing device for crushing concrete.
  • a solid tooth for a small hydraulic excavator has been described as a tooth for a bucket.
  • the present invention is also applicable to a tooth for a large excavator while being used so as to cover the adapter of the bucket. Wear-resistant parts can be applied.
  • the wear-resistant component and the manufacturing method thereof according to the present invention can be particularly advantageously applied to the wear-resistant component having a built-up layer and the manufacturing method.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Component Parts Of Construction Machinery (AREA)
  • Earth Drilling (AREA)

Abstract

One example of this wear-resistant component is a tooth (20) that is provided with a base (25) that comprises a first metal and with a build-up layer (27) that is disposed in contact with the base (25) so as to cover a covered region (25A) that is one section of the surface of the base (25). The surface of the base (25) has build-up edges (29) that are boundaries between the covered region (25A) and an exposed region (25B), which is a region that is not the covered region (25A), and are forged surfaces at which the exposed region (25B) and the surface (27A) of the build-up layer (27) constitute the same surface.

Description

耐摩耗部品およびその製造方法Wear-resistant parts and method for manufacturing the same
　本発明は耐摩耗部品およびその製造方法に関するものである。 The present invention relates to a wear-resistant component and a manufacturing method thereof.
　油圧ショベル、ブルドーザ、ホイールローダなど、土砂の存在する環境下で稼働する作業機械を構成する部品として、リッパ、ツースなどの耐摩耗部品が用いられる。耐摩耗部品において特に高い耐摩耗性が要求される領域には、肉盛層が形成される場合がある。肉盛層としては、たとえば鋼からなる母材中に硬質粒子が分散したものを採用することができる。肉盛層は、たとえば肉盛溶接により形成することができる（たとえば、特開２００８－７６３号公報（特許文献１）および特開平８－４７７７４号公報（特許文献２）参照）。 Wear-resistant parts such as ripper and tooth are used as parts constituting work machines that operate in the presence of earth and sand, such as hydraulic excavators, bulldozers, and wheel loaders. An overlay layer may be formed in a region where particularly high wear resistance is required in the wear-resistant component. As the build-up layer, for example, a material in which hard particles are dispersed in a base material made of steel can be used. The build-up layer can be formed by, for example, build-up welding (see, for example, Japanese Patent Laid-Open No. 2008-763 (Patent Document 1) and Japanese Patent Laid-Open No. 8-47774 (Patent Document 2)).
特開２００８－７６３号公報JP 2008-763 A 特開平８－４７７７４号公報JP-A-8-47774
　肉盛層を有する耐摩耗部品は、所望の形状に成形されたベース部を準備し、ベース部のうち特に高い耐摩耗性が要求される領域を覆うように肉盛層を形成することにより得られる。肉盛層の形成により耐摩耗部品の耐久性を向上させることができる一方で、形成された肉盛層に起因したデメリットが発生する場合がある。たとえば、油圧ショベルのバケットのツースに肉盛層を形成した場合、ツースの土砂への貫入抵抗が上昇する場合がある。 A wear-resistant part having a build-up layer is obtained by preparing a base part molded in a desired shape and forming the build-up layer so as to cover an area of the base part that requires particularly high wear resistance. It is done. While the build-up layer can improve the durability of the wear-resistant component, there may be a demerit caused by the formed build-up layer. For example, when a build-up layer is formed on the tooth of a bucket of a hydraulic excavator, the penetration resistance of the tooth into the earth and sand may increase.
　本発明は、肉盛層を有する耐摩耗部品において肉盛層の形成に起因したデメリットを抑制することを目的とする。 An object of the present invention is to suppress demerits caused by the formation of a built-up layer in a wear-resistant part having a built-up layer.
　本発明に従った耐摩耗部品は、第１金属からなるベース部と、ベース部の表面の一部である被覆領域を覆うようにベース部に接触して配置された肉盛層と、を備える。ベース部の表面の、被覆領域と被覆領域以外の領域である露出領域との境界である肉盛端部において、露出領域と肉盛層の表面とは同一面を構成する鍛造面となっている。 A wear-resistant component according to the present invention includes a base portion made of a first metal and a built-up layer disposed in contact with the base portion so as to cover a covering region that is a part of the surface of the base portion. . In the built-up end that is the boundary between the covered region and the exposed region that is a region other than the covered region, the exposed region and the surface of the built-up layer form a forged surface that forms the same surface. .
　上述のように、肉盛層は、ベース部の表面上に肉盛溶接などの手法によって形成される。肉盛層が形成された耐摩耗部品では、ベース部の表面の、肉盛層に覆われた領域（被覆領域）と被覆領域以外の領域（露出領域）との境界である肉盛端部において、肉盛層の表面とベース部の露出領域との間に段差が形成されるのが一般的である。この段差は、肉盛層の形成に起因したデメリットの原因となる。たとえば、油圧ショベルのバケットのツースに肉盛層が形成される場合がある。肉盛層の形成によりツースの耐摩耗性が向上する一方で、上記段差が形成されることによりツースの土砂に対する貫入抵抗が上昇する場合がある。他の部品と接触しつつ使用される部品に肉盛層が形成された場合、上記段差に起因して、当該他の部品との所望の接触状態が十分に達成できない場合がある。 As described above, the overlay layer is formed on the surface of the base portion by a technique such as overlay welding. In wear-resistant parts with a built-up layer, at the built-up end, which is the boundary between the area covered by the built-up layer (covered area) and the area other than the covered area (exposed area) on the surface of the base part In general, a step is formed between the surface of the overlay layer and the exposed region of the base portion. This level | step difference becomes a cause of the demerit resulting from formation of the overlaying layer. For example, a built-up layer may be formed on the tooth of a bucket of a hydraulic excavator. While the wear resistance of the tooth is improved by the formation of the overlay layer, the penetration resistance of the tooth with respect to the earth and sand may be increased due to the formation of the step. When a built-up layer is formed on a component that is used while being in contact with another component, a desired contact state with the other component may not be sufficiently achieved due to the step.
　本発明の耐摩耗部品では、肉盛端部において、ベース部の露出領域と肉盛層の表面とが同一面を構成する。そのため、上記段差に起因した肉盛層の形成によるデメリットが抑制される。また、肉盛端部が鍛造面に含まれることにより、切削等によってベース部の露出領域と肉盛層の表面とが同一面となるように加工する工程を省略することが可能となる。そのため、硬度差の大きい肉盛端部の加工、および硬度の高い肉盛層の加工を回避することができる。このように、本発明の耐摩耗部品によれば、肉盛層を有する耐摩耗部品において肉盛層の形成に起因したデメリットを抑制することが可能な耐摩耗部品を提供することができる。 In the wear-resistant part of the present invention, the exposed area of the base part and the surface of the built-up layer form the same surface at the built-up end. Therefore, the demerit by formation of the build-up layer resulting from the said level | step difference is suppressed. In addition, by including the built-up end portion in the forged surface, it is possible to omit the step of processing so that the exposed region of the base portion and the surface of the built-up layer are flush with each other by cutting or the like. Therefore, processing of the built-up end portion having a large hardness difference and processing of the built-up layer having high hardness can be avoided. Thus, according to the wear-resistant component of the present invention, it is possible to provide a wear-resistant component capable of suppressing the disadvantages caused by the formation of the build-up layer in the wear-resistant component having the build-up layer.
　上記耐摩耗部品において、上記肉盛層は、第２金属からなる母相と、母相中に分散する硬質粒子と、を含んでいてもよい。このようにすることにより、耐摩耗性に優れた肉盛層を容易に形成することができる。 In the wear-resistant component, the build-up layer may include a parent phase made of the second metal and hard particles dispersed in the parent phase. By doing in this way, the build-up layer excellent in abrasion resistance can be formed easily.
　上記耐摩耗部品において、肉盛層の表面から硬質粒子の平均粒径以内の領域である肉盛層表層領域内に位置する硬質粒子は、肉盛層に埋め込まれた状態で並んで配置されていてもよい。このようにすることにより、肉盛層の表面から硬質粒子が大きく突出して配置されることが抑制される。その結果、耐摩耗部品の使用中における硬質粒子の脱落が抑制される。なお、硬質粒子の平均粒径は、肉盛層の表面に垂直な断面を光学顕微鏡にて観察し、観察される硬質粒子１０個の直径の平均値を計算することにより得ることができる。 In the wear-resistant component, the hard particles located in the surface layer region of the built-up layer that is within the average particle diameter of the hard particles from the surface of the built-up layer are arranged side by side in a state embedded in the built-up layer. May be. By doing in this way, it is suppressed that a hard particle protrudes greatly from the surface of the build-up layer. As a result, falling off of the hard particles during use of the wear resistant part is suppressed. The average particle diameter of the hard particles can be obtained by observing a cross section perpendicular to the surface of the build-up layer with an optical microscope, and calculating the average value of the diameters of 10 observed hard particles.
　上記耐摩耗部品において、上記肉盛層表層領域内に位置する上記硬質粒子は、上記肉盛層の表面に接するように配置されてもよい。これにより、肉盛層の表面から露出する硬質粒子の領域がわずかとなり、硬質粒子の脱落が抑制される。 In the wear resistant part, the hard particles located in the surface layer region of the build-up layer may be arranged so as to contact the surface of the build-up layer. Thereby, the area | region of the hard particle exposed from the surface of an overlaying layer becomes few, and omission of a hard particle is suppressed.
　上記耐摩耗部品において、上記肉盛層表層領域内に位置する上記硬質粒子の、上記肉盛層の表面から露出する領域に対応する中心角は鋭角（９０°未満）であってもよい。これにより、肉盛層の表面から露出する硬質粒子の領域がわずかとなり、硬質粒子の脱落が抑制される。 In the wear-resistant component, a central angle corresponding to a region exposed from the surface of the buildup layer of the hard particles located in the surface layer region of the buildup layer may be an acute angle (less than 90 °). Thereby, the area | region of the hard particle exposed from the surface of an overlaying layer becomes few, and omission of a hard particle is suppressed.
　上記耐摩耗部品において、上記肉盛層は、上記肉盛層と上記ベース部との界面を含む領域において、上記ベース部に向けて突出する突出部を含んでいてもよい。これにより、ベース部から肉盛層が剥離することが抑制される。 In the wear-resistant component, the build-up layer may include a protruding portion that protrudes toward the base portion in a region including an interface between the build-up layer and the base portion. Thereby, it is suppressed that a build-up layer peels from a base part.
　上記耐摩耗部品において、上記突出部には、上記硬質粒子の少なくとも一部が進入していてもよい。これにより、ベース部から肉盛層が剥離することが、より確実に抑制される。 In the wear-resistant component, at least a part of the hard particles may enter the protruding portion. Thereby, it is suppressed more reliably that a build-up layer peels from a base part.
　本発明に従った耐摩耗部品の製造方法は、第１金属からなるベース部材を準備する工程と、ベース部材の表面の一部である被覆領域に接触して被覆領域を覆うように、肉盛層を形成する工程と、ベース部の表面の、被覆領域と被覆領域以外の領域である露出領域との境界である肉盛端部が加工されるように、肉盛層が形成されたベース部材を鍛造する工程と、を備える。 The method of manufacturing a wear-resistant component according to the present invention includes a step of preparing a base member made of a first metal, and overlaying so as to cover and cover the coating region that is a part of the surface of the base member. The base member on which the build-up layer is formed so that the build-up end portion that is the boundary between the step of forming the layer and the exposed region that is the region other than the cover region on the surface of the base portion is processed Forging.
　本発明の耐摩耗部品の製造方法では、肉盛端部が加工されるように、肉盛層が形成されたベース部材が鍛造される。そのため、肉盛端部において、肉盛層の表面とベース部の露出領域とが同一面を構成する鍛造面である耐摩耗部品が製造され、上記段差に起因した肉盛層の形成によるデメリットが抑制される。また、肉盛端部が鍛造面に含まれることにより、切削等によってベース部の露出領域と肉盛層の表面とが同一面となるように加工する工程を省略することが可能となる。そのため、硬度差の大きい肉盛端部の加工、および硬度の高い肉盛層の加工を回避することができる。このように、本発明の耐摩耗部品の製造方法によれば、肉盛層を有する耐摩耗部品において肉盛層の形成に起因したデメリットを抑制することが可能な耐摩耗部品を製造することができる。 In the wear-resistant component manufacturing method of the present invention, the base member on which the build-up layer is formed is forged so that the build-up end portion is processed. Therefore, wear-resistant parts that are forged surfaces in which the surface of the built-up layer and the exposed region of the base portion constitute the same surface are manufactured at the built-up end, and there are disadvantages due to the formation of the built-up layer due to the above steps. It is suppressed. In addition, by including the built-up end portion in the forged surface, it is possible to omit the step of processing so that the exposed region of the base portion and the surface of the built-up layer are flush with each other by cutting or the like. Therefore, processing of the built-up end portion having a large hardness difference and processing of the built-up layer having high hardness can be avoided. As described above, according to the method for manufacturing a wear-resistant component of the present invention, it is possible to manufacture a wear-resistant component capable of suppressing the disadvantages caused by the formation of the build-up layer in the wear-resistant component having the build-up layer. it can.
　上記耐摩耗部品の製造方法において、肉盛層が形成されたベース部材を鍛造する工程では、肉盛層が形成されたベース部材が熱間鍛造されてもよい。熱間鍛造を採用することにより、肉盛層が形成されたベース部材を容易に鍛造することが可能となる。 In the method for manufacturing a wear-resistant component, in the step of forging the base member on which the overlay layer is formed, the base member on which the overlay layer is formed may be hot forged. By adopting hot forging, it becomes possible to easily forge the base member on which the build-up layer is formed.
　上記耐摩耗部品の製造方法において、肉盛層を形成する工程では、第２金属からなる母相と、母相中に分散する硬質粒子と、を含む肉盛層が形成されてもよい。このようにすることにより、耐摩耗性に優れた肉盛層を容易に形成することができる。 In the method for manufacturing a wear-resistant component, in the step of forming the build-up layer, a build-up layer including a parent phase made of the second metal and hard particles dispersed in the parent phase may be formed. By doing in this way, the build-up layer excellent in abrasion resistance can be formed easily.
　以上の説明から明らかなように、本発明の耐摩耗部品およびその製造方法によれば、肉盛層を有する耐摩耗部品において肉盛層の形成に起因したデメリットを抑制することができる。 As is clear from the above description, according to the wear-resistant component and the manufacturing method thereof of the present invention, it is possible to suppress demerits caused by the formation of the build-up layer in the wear-resistant component having the build-up layer.
油圧ショベルのバケットの構造を示す概略斜視図である。It is a schematic perspective view which shows the structure of the bucket of a hydraulic shovel. ツースの構造を示す概略平面図である。It is a schematic plan view which shows the structure of a tooth. 図２の線分ＩＩＩ－ＩＩＩに沿う断面を示す概略断面図である。FIG. 3 is a schematic sectional view showing a section taken along line III-III in FIG. 2. 比較例のツースの構造を示す概略断面図である。It is a schematic sectional drawing which shows the structure of the tooth of a comparative example. 肉盛層の表面付近の構造を示す概略断面図である。It is a schematic sectional drawing which shows the structure of the surface vicinity of an overlaying layer. 肉盛層とベース部との界面付近の構造を示す概略断面図である。It is a schematic sectional drawing which shows the structure of the interface vicinity of a building-up layer and a base part. ツースの製造方法の概略を示すフローチャートである。It is a flowchart which shows the outline of the manufacturing method of a tooth. ツースの製造方法を説明するための概略断面図である。It is a schematic sectional drawing for demonstrating the manufacturing method of a tooth. ツースの製造方法を説明するための概略断面図である。It is a schematic sectional drawing for demonstrating the manufacturing method of a tooth. 肉盛層の形成方法を説明するための概略断面図である。It is a schematic sectional drawing for demonstrating the formation method of an overlaying layer. ツースの断面を示す写真である。It is a photograph which shows the cross section of a tooth. 肉盛層の表面付近の光学顕微鏡写真である（実施例）。It is an optical microscope photograph of the surface vicinity of the overlaying layer (Example). 肉盛層の表面付近の光学顕微鏡写真である（比較例）。It is an optical microscope photograph of the surface vicinity of the overlaying layer (comparative example). 肉盛層とベース部との界面付近の光学顕微鏡写真である（実施例）。It is an optical micrograph of the interface vicinity of a building-up layer and a base part (Example). 肉盛層とベース部との界面付近の光学顕微鏡写真である（比較例）。It is an optical microscope photograph of the interface vicinity of an overlaying layer and a base part (comparative example). 貫入抵抗試験に供したツースの写真である（実施例）。It is the photograph of the tooth | gear used for the penetration resistance test (Example). 貫入抵抗試験に供したツースの写真である（比較例）。It is the photograph of the tooth | gear used for the penetration resistance test (comparative example). 貫入抵抗試験の結果を示す図である。It is a figure which shows the result of a penetration resistance test.
　以下、本発明の一実施の形態について説明する。なお、以下の図面において同一または相当する部分には同一の参照番号を付し、その説明は繰り返さない。 Hereinafter, an embodiment of the present invention will be described. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.
　油圧ショベルのバケットのツースを例に、本実施の形態の耐摩耗部品について説明する。図１は、油圧ショベルのバケットの構造を示す概略斜視図である。図２は、ツースの構造を示す概略平面図である。図３は、図２の線分ＩＩＩ－ＩＩＩに沿う断面を示す概略断面図である。 The wear-resistant parts of the present embodiment will be described by taking an example of a tooth of a bucket of a hydraulic excavator. FIG. 1 is a schematic perspective view showing the structure of a bucket of a hydraulic excavator. FIG. 2 is a schematic plan view showing the structure of the tooth. 3 is a schematic cross-sectional view showing a cross section taken along line III-III in FIG.
　図１を参照して、バケット１は、油圧ショベルのアーム（図示しない）の先端に装着され、土砂を掘削する。バケット１は、板状部材から構成され、開口を有する本体１０と、本体１０の開口外周部１２の掘削側からその一部が突出するように本体１０に取り付けられた複数の（図１に示すバケット１においては３つの）ツース２０と、本体１０の、ツース２０が取り付けられる側とは反対側に配置された装着部３０とを備えている。バケット１は、装着部３０において油圧ショベルのアームに支持される。掘削時には、バケット１は、ツース２０から土砂へと進入する。そのため、ツース２０には、高い耐摩耗性（耐土砂摩耗性）が要求される。ツース２０は、土砂に接触する用途に使用される機械部品である耐土砂摩耗部品である。 Referring to FIG. 1, bucket 1 is attached to the tip of a hydraulic excavator arm (not shown) to excavate earth and sand. The bucket 1 is composed of a plate-like member, and a plurality of (shown in FIG. 1) attached to the main body 10 such that a main body 10 having an opening and a part of the main body 10 project from the excavation side of the outer periphery 12 of the opening The bucket 1 includes three) teeth 20 and a mounting portion 30 disposed on the main body 10 on the side opposite to the side on which the teeth 20 are attached. Bucket 1 is supported by an arm of a hydraulic excavator at mounting portion 30. During excavation, the bucket 1 enters the earth and sand from the tooth 20. Therefore, the tooth 20 is required to have high wear resistance (earth and sand wear resistance). The tooth 20 is an earth and sand wear resistant part that is a machine part used for an application in contact with earth and sand.
　ツース２０は、図２に示すように、先端２１と、基端２２とを含む。ツース２０は、基端２２側において本体１０に取り付けられ、先端２１側がバケット１の開口外周部１２から突出する。ツース２０は、他の部品である本体１０と接触しつつ使用される。バケット１は、ツース２０の先端２１側から土砂へと進入する。そのため、ツース２０の先端２１側には、特に高い耐摩耗性（耐土砂摩耗性）が要求される。 The tooth 20 includes a distal end 21 and a proximal end 22, as shown in FIG. The tooth 20 is attached to the main body 10 on the proximal end 22 side, and the distal end 21 side protrudes from the opening outer peripheral portion 12 of the bucket 1. The tooth 20 is used while being in contact with the main body 10 which is another part. The bucket 1 enters the earth and sand from the tip 21 side of the tooth 20. Therefore, particularly high wear resistance (earth and sand wear resistance) is required on the tip 21 side of the tooth 20.
　図３を参照して、ツース２０は、第１金属からなるベース部２５と、ベース部２５の表面の一部である被覆領域２５Ａを覆うようにベース部２５に接触して配置される肉盛層２７と、を備える。ベース部２５を構成する第１金属としては、たとえばＪＩＳ規格に規定される機械構造用炭素鋼または機械構造用合金鋼（たとえばＳ４５Ｃ、ＳＣＭ４３５のほか、同等量の炭素を含むＳＭｎ鋼、ＳＣｒ鋼、ＳＣＭ鋼など）などを採用することができる。ベース部２５の表面の、被覆領域２５Ａと被覆領域２５Ａ以外の領域である露出領域２５Ｂとの境界である肉盛端部２９において、露出領域２５Ｂと肉盛層２７の表面２７Ａとは同一面を構成する鍛造面となっている。肉盛層２７の表面２７Ａは、全域にわたって鍛造面となっている。 Referring to FIG. 3, the tooth 20 is built up in contact with the base portion 25 so as to cover the base portion 25 made of the first metal and the covering region 25 </ b> A which is a part of the surface of the base portion 25. Layer 27. As the first metal constituting the base portion 25, for example, carbon steel for machine structure or alloy steel for machine structure (for example, S45C, SCM435, SMn steel, SCr steel containing an equivalent amount of carbon, SCM steel etc.) can be employed. In the built-up end portion 29 that is the boundary between the covered region 25A and the exposed region 25B that is a region other than the covered region 25A on the surface of the base portion 25, the exposed region 25B and the surface 27A of the built-up layer 27 are flush with each other. It is a forged surface to constitute. The surface 27A of the overlay layer 27 is a forged surface over the entire area.
　図４は、肉盛層を有する比較例のツースの構造を示す概略断面図である。一般に、ツースの先端付近の耐摩耗性向上を目的として肉盛層を形成する場合、所望の形状を有する鋼製のベース部に肉盛層が形成される。図４を参照して、肉盛層を有する一般的なツースである比較例のツース９２０は、先端９２１と、基端９２２とを含む。ツース９２０の先端９２１側には肉盛層９２７が形成されている。肉盛層９２７は、所望の形状に成形されたベース部９２５の被覆領域９２５Ａを覆うように、たとえば肉盛溶接により形成される。そのため、被覆領域９２５Ａと被覆領域９２５Ａ以外の領域である露出領域９２５Ｂ，９２５Ｃとの境界である肉盛端部９２９Ａ，９２９Ｂにおいて露出領域９２５Ｂ，９２５Ｃと肉盛層９２７の表面９２７Ａとの間に段差が形成される。この段差に起因して、ツース９２０の土砂への貫入抵抗が大きくなる。また、ベース部９２５の成形後に肉盛層９２７を形成するため、先端９２１付近に肉盛層９２７を形成することは困難である。そのため、先端９２１を含む領域には肉盛層９２７が形成されていない領域である先端側露出領域９２５Ｃが形成される。先端側露出領域９２５Ｃの耐摩耗性が低いことに起因して、ツース９２０の摩耗の進行が速くなり、交換頻度が増加する。 FIG. 4 is a schematic cross-sectional view showing the structure of a tooth of a comparative example having a built-up layer. Generally, when forming a built-up layer for the purpose of improving wear resistance near the tip of the tooth, the built-up layer is formed on a steel base portion having a desired shape. Referring to FIG. 4, a comparative tooth 920 that is a general tooth having a built-up layer includes a distal end 921 and a proximal end 922. A built-up layer 927 is formed on the tip 921 side of the tooth 920. The overlay layer 927 is formed, for example, by overlay welding so as to cover the covering region 925A of the base portion 925 formed in a desired shape. Therefore, there is a step between the exposed regions 925B and 925C and the surface 927A of the built-up layer 927 at the built-up end portions 929A and 929B that are boundaries between the covered region 925A and the exposed regions 925B and 925C that are regions other than the covered region 925A. Is formed. Due to this step, the penetration resistance of the tooth 920 into the earth and sand increases. Further, since the build-up layer 927 is formed after the base portion 925 is formed, it is difficult to form the build-up layer 927 near the tip 921. Therefore, a tip side exposed region 925 </ b> C, which is a region where the overlay layer 927 is not formed, is formed in a region including the tip 921. Due to the low wear resistance of the tip side exposed region 925C, the progress of wear of the tooth 920 becomes faster, and the replacement frequency increases.
　図３を参照して、本実施の形態におけるツース２０によれば、肉盛端部２９において露出領域２５Ｂと肉盛層２７の表面２７Ａとが同一面を形成することにより、肉盛端部２９における段差に起因した貫入抵抗の上昇を回避することができる。肉盛端部２９が鍛造面に含まれることにより、切削等によって露出領域２５Ｂと肉盛層２７の表面２７Ａとが同一面となるように加工する工程を省略することが可能となる。そのため、硬度差の大きい肉盛端部２９の加工、および硬度の高い肉盛層２７の加工を回避することができる。このように、本実施の形態におけるツース２０によれば、肉盛層２７の形成に起因したデメリットを抑制することができる。また、ベース部材上に肉盛層を形成した後、鍛造を実施して先端２１を含む領域を成形すれば、図３に示すように先端２１を含む領域を肉盛層２７に覆われたものとすることが容易となり、高い耐摩耗性を有するツース２０を得ることができる。 With reference to FIG. 3, according to the tooth 20 in the present embodiment, the exposed region 25 </ b> B and the surface 27 </ b> A of the built-up layer 27 form the same surface at the built-up end 29, thereby It is possible to avoid an increase in penetration resistance due to a step in the case. By including the built-up end portion 29 in the forged surface, it is possible to omit the step of processing so that the exposed region 25B and the surface 27A of the built-up layer 27 are flush with each other by cutting or the like. Therefore, the processing of the built-up end portion 29 having a large hardness difference and the processing of the built-up layer 27 having a high hardness can be avoided. Thus, according to the tooth 20 in this Embodiment, the demerit resulting from formation of the build-up layer 27 can be suppressed. Further, after forming a built-up layer on the base member, forging is performed to form a region including the tip 21, and the region including the tip 21 is covered with the built-up layer 27 as shown in FIG. Thus, the tooth 20 having high wear resistance can be obtained.
　次に、肉盛層２７の構造について説明する。図５は、肉盛層の表面付近の構造を示す概略断面図である。図６は、肉盛層とベース部との界面付近の構造を示す概略断面図である。図５および図６を参照して、肉盛層２７は、第２金属からなる母相９５と、母相９５中に分散する硬質粒子９１と、を含んでいる。母相９５を構成する第２金属は、たとえば溶接ワイヤに由来する金属とベース部２５を構成する第１金属とが混合されたものとすることができる。硬質粒子９１としては、母相９５よりも硬度が高い粒子、たとえば超硬合金からなる粒子を採用することができる。肉盛層２７は、ベース部２５よりも耐摩耗性（耐土砂摩耗性）が高い。 Next, the structure of the overlay layer 27 will be described. FIG. 5 is a schematic cross-sectional view showing a structure near the surface of the overlay layer. FIG. 6 is a schematic cross-sectional view showing a structure near the interface between the build-up layer and the base portion. Referring to FIGS. 5 and 6, build-up layer 27 includes a mother phase 95 made of a second metal and hard particles 91 dispersed in mother phase 95. The second metal constituting the parent phase 95 can be, for example, a mixture of a metal derived from a welding wire and a first metal constituting the base portion 25. As the hard particles 91, particles having a hardness higher than that of the parent phase 95, for example, particles made of a cemented carbide can be used. The build-up layer 27 has higher wear resistance (earth and sand wear resistance) than the base portion 25.
　図５を参照して、肉盛層２７の表面２７Ａは鍛造面となっている。肉盛層２７の表面２７Ａから硬質粒子９１の平均粒径以内の領域である肉盛層表層領域２７Ｂ内に位置する硬質粒子９１は、肉盛層２７に埋め込まれた状態で並んで配置される。これにより、肉盛層２７の表面２７Ａから硬質粒子９１が大きく突出して配置されることが抑制される。その結果、ツース２０の使用中における硬質粒子９１の脱落が抑制され、ツース２０の耐摩耗性が向上している。 Referring to FIG. 5, the surface 27A of the built-up layer 27 is a forged surface. The hard particles 91 located in the built-up layer surface layer region 27 </ b> B, which is a region within the average particle diameter of the hard particles 91 from the surface 27 </ b> A of the built-up layer 27, are arranged side by side while being embedded in the built-up layer 27. . Thereby, it is suppressed that the hard particles 91 are greatly protruded from the surface 27 </ b> A of the built-up layer 27. As a result, falling off of the hard particles 91 during use of the tooth 20 is suppressed, and the wear resistance of the tooth 20 is improved.
　肉盛層表層領域２７Ｂ内に位置する硬質粒子９１は、図６に示すように肉盛層２７の表面２７Ａに接するように配置されていてもよい。これにより、肉盛層２７の表面２７Ａから露出する硬質粒子９１の領域がわずかとなり、硬質粒子９１の脱落が抑制される。 The hard particles 91 located in the build-up layer surface layer region 27B may be arranged so as to be in contact with the surface 27A of the build-up layer 27 as shown in FIG. Thereby, the area | region of the hard particle 91 exposed from the surface 27A of the build-up layer 27 becomes few, and omission of the hard particle 91 is suppressed.
　硬質粒子９１の、肉盛層２７の表面２７Ａから露出する領域に対応する中心角θは鋭角（９０°未満）であることが好ましい。これにより、肉盛層２７の表面２７Ａから露出する硬質粒子９１の領域がわずかとなり、硬質粒子９１の脱落が抑制される。 The central angle θ corresponding to the region of the hard particles 91 exposed from the surface 27A of the built-up layer 27 is preferably an acute angle (less than 90 °). Thereby, the area | region of the hard particle 91 exposed from the surface 27A of the build-up layer 27 becomes few, and omission of the hard particle 91 is suppressed.
　図６を参照して、肉盛層２７は、肉盛層２７とベース部２５との界面を含む領域において、ベース部２５に向けて突出する突出部９９を含む。突出部９９によるアンカー効果により、ベース部２５から肉盛層２７が剥離することが抑制される。突出部９９には、硬質粒子９１の少なくとも一部が進入している。これにより、ベース部２５から肉盛層２７が剥離することがより確実に抑制される。突出部９９に進入している硬質粒子９１とベース部２５との間には肉盛層２７の母相９５が介在している。突出部９９に進入している硬質粒子９１とベース部２５とは、接触していない。硬質粒子９１の中心は、突出部９９の外部に位置している（硬質粒子９１の体積の１／２未満の領域が突出部９９内に進入している。）。各突出部９９内には、１つの硬質粒子９１が進入している。各突出部９９の深さは、当該突出部９９に進入する硬質粒子９１の半径よりも小さい。 Referring to FIG. 6, build-up layer 27 includes a protruding portion 99 that protrudes toward base portion 25 in a region including the interface between build-up layer 27 and base portion 25. Due to the anchor effect by the protruding portion 99, the build-up layer 27 is prevented from peeling from the base portion 25. At least a part of the hard particles 91 enters the protruding portion 99. Thereby, peeling of the build-up layer 27 from the base part 25 is suppressed more reliably. Between the hard particles 91 entering the projecting portion 99 and the base portion 25, the parent phase 95 of the built-up layer 27 is interposed. The hard particles 91 entering the protruding portion 99 and the base portion 25 are not in contact with each other. The center of the hard particle 91 is located outside the protrusion 99 (a region that is less than ½ of the volume of the hard particle 91 enters the protrusion 99). One hard particle 91 enters each protrusion 99. The depth of each protrusion 99 is smaller than the radius of the hard particles 91 entering the protrusion 99.
　次に、図７～図１０を参照して、本実施の形態における耐摩耗部品であるツース２０の製造方法について説明する。図７は、ツースの製造方法の概略を示すフローチャートである。図８および図９は、ツースの製造方法を説明するための概略断面図である。図１０は、肉盛層の形成方法を説明するための概略断面図である。 Next, with reference to FIGS. 7 to 10, a method of manufacturing the tooth 20 that is a wear-resistant component in the present embodiment will be described. FIG. 7 is a flowchart showing an outline of a tooth manufacturing method. 8 and 9 are schematic cross-sectional views for explaining the manufacturing method of the tooth. FIG. 10 is a schematic cross-sectional view for explaining a method for forming the build-up layer.
　図７を参照して、本実施の形態におけるツース２０の製造方法では、まず工程（Ｓ１０）としてベース部材準備工程が実施される。この工程（Ｓ１０）では、図８を参照して、ツース２０のベース部２５となるべきベース部材５０が準備される。ベース部材５０は、第１金属からなる。ベース部材５０は円筒形状である。ベース部材５０は、一方の端面５２と、他方の端面５３と、一方の端面５２と他方の端面５３とを接続する側面５１とを含む円筒状の形状を有している。一方の端面５２と側面５１とが接続される領域には、第１面取り部５２Ａが形成されている。他方の端面５３と側面５１とが接続される領域には、第２面取り部５３Ａが形成されている。図８および図３を参照して、ベース部材５０の一方の端面５２側がツース２０の先端２１側に対応し、ベース部材５０の他方の端面５３側がツース２０の基端２２側に対応する。 Referring to FIG. 7, in the manufacturing method of tooth 20 in the present embodiment, a base member preparation step is first performed as a step (S10). In this step (S10), with reference to FIG. 8, a base member 50 to be the base portion 25 of the tooth 20 is prepared. The base member 50 is made of a first metal. The base member 50 has a cylindrical shape. The base member 50 has a cylindrical shape including one end surface 52, the other end surface 53, and a side surface 51 connecting the one end surface 52 and the other end surface 53. A first chamfered portion 52A is formed in a region where one end surface 52 and the side surface 51 are connected. A second chamfered portion 53 </ b> A is formed in a region where the other end surface 53 and the side surface 51 are connected. 8 and 3, one end surface 52 side of the base member 50 corresponds to the distal end 21 side of the tooth 20, and the other end surface 53 side of the base member 50 corresponds to the proximal end 22 side of the tooth 20.
　次に、工程（Ｓ２０）として肉盛層形成工程が実施される。この工程（Ｓ２０）では、図８および図９を参照して、工程（Ｓ１０）において準備されたベース部材５０の表面の一部である被覆領域５１Ａに接触して被覆領域５１Ａを覆うように肉盛層６０が形成される。肉盛層６０は、後述する熱間鍛造が実施されることによりベース部２５の所望の領域を覆うように形成される。被覆領域５１Ａは、たとえば予め有限要素法を用いた熱間鍛造のシミュレーションを行うことにより決定することができる。本実施の形態では、図９を参照して、側面５１の一方の端面５２側、第１面取り部５２Ａおよび一方の端面５２を覆うように、肉盛層６０が形成される。 Next, a build-up layer forming step is performed as a step (S20). In this step (S20), referring to FIG. 8 and FIG. 9, the meat is formed so as to cover the covering region 51A in contact with the covering region 51A which is a part of the surface of the base member 50 prepared in the step (S10). A built-up layer 60 is formed. The overlay layer 60 is formed so as to cover a desired region of the base portion 25 by performing hot forging described later. The covering region 51A can be determined, for example, by performing a hot forging simulation using a finite element method in advance. In the present embodiment, referring to FIG. 9, build-up layer 60 is formed so as to cover one end surface 52 side of side surface 51, first chamfered portion 52 </ b> A and one end surface 52.
　肉盛層６０の形成は、たとえば以下のように炭酸ガスアーク溶接法を利用した肉盛溶接により実施することができる。まず、肉盛層形成装置について説明する。図１０を参照して、肉盛層形成装置は、溶接トーチ７０と、硬質粒子供給ノズル８０とを備えている。溶接トーチ７０は、中空円筒形状を有する溶接ノズル７１と、溶接ノズル７１の内部に配置され、電源（図示しない）に接続されたコンタクトチップ７２とを含む。コンタクトチップ７２に接触しつつ、溶接ワイヤ７３が溶接ノズル７１の先端側へと連続的に供給される。溶接ワイヤとしては、たとえばＪＩＳ規格ＹＧＷ１２を採用することができる。溶接ノズル７１とコンタクトチップ７２との隙間は、シールドガスの流路となっている。当該流路を流れるシールドガスは、溶接ノズル７１の先端から吐出される。硬質粒子供給ノズル８０は、中空円筒状の形状を有している。硬質粒子供給ノズル８０内には硬質粒子９１が供給され、硬質粒子供給ノズル８０の先端から硬質粒子９１が吐出される。 The build-up layer 60 can be formed, for example, by build-up welding using a carbon dioxide arc welding method as follows. First, the overlay layer forming apparatus will be described. Referring to FIG. 10, the overlay layer forming apparatus includes a welding torch 70 and a hard particle supply nozzle 80. The welding torch 70 includes a welding nozzle 71 having a hollow cylindrical shape, and a contact tip 72 disposed inside the welding nozzle 71 and connected to a power source (not shown). While contacting the contact tip 72, the welding wire 73 is continuously supplied to the distal end side of the welding nozzle 71. As the welding wire, for example, JIS standard YGW12 can be adopted. A gap between the welding nozzle 71 and the contact tip 72 is a shield gas flow path. The shield gas flowing through the flow path is discharged from the tip of the welding nozzle 71. The hard particle supply nozzle 80 has a hollow cylindrical shape. Hard particles 91 are supplied into the hard particle supply nozzle 80, and the hard particles 91 are discharged from the tip of the hard particle supply nozzle 80.
　上記肉盛層形成装置を用いて肉盛層６０を以下の手順で形成することができる。ベース部材５０を一方の電極とし、溶接ワイヤ７３を他方の電極としてベース部材５０と溶接ワイヤ７３との間に電圧を印加すると、溶接ワイヤ７３とベース部材５０との間にアーク７４が形成される。アーク７４は、溶接ノズル７１の先端から矢印βに沿って吐出されるシールドガスによって、周囲の空気から遮断される。シールドガスとしては、たとえば二酸化炭素を採用することができる。アーク７４の熱により、ベース部材５０の一部および溶接ワイヤ７３の先端が溶融する。溶接ワイヤ７３の先端が溶融して形成された液滴は、ベース部材５０の溶融した領域へと移行する。これにより、溶融したベース部材５０と溶接ワイヤ７３とが混ざり合った液体領域である溶融池９２が形成される。溶融池９２には、硬質粒子供給ノズル８０から吐出された硬質粒子９１が供給される。 The built-up layer 60 can be formed by the following procedure using the built-up layer forming apparatus. When a voltage is applied between the base member 50 and the welding wire 73 using the base member 50 as one electrode and the welding wire 73 as the other electrode, an arc 74 is formed between the welding wire 73 and the base member 50. . The arc 74 is cut off from the surrounding air by the shielding gas discharged along the arrow β from the tip of the welding nozzle 71. As the shielding gas, for example, carbon dioxide can be employed. Part of the base member 50 and the tip of the welding wire 73 are melted by the heat of the arc 74. The droplet formed by melting the tip of the welding wire 73 moves to the molten region of the base member 50. Thereby, a molten pool 92 which is a liquid region in which the melted base member 50 and the welding wire 73 are mixed is formed. Hard particles 91 discharged from the hard particle supply nozzle 80 are supplied to the molten pool 92.
　肉盛溶接装置を構成する溶接トーチ７０および硬質粒子供給ノズル８０がベース部材５０に対して矢印αの向きに相対的に移動すると、溶融池９２が形成される位置が順次移動し、先に形成された溶融池９２は凝固して、肉盛層６０となる。肉盛層６０は、溶融池９２が凝固して形成された母相９５と、母相９５中に分散する硬質粒子９１とを含む。以上の手順により、ベース部材５０の表面の被覆領域５１Ａを覆う肉盛層６０が形成される。肉盛層６０が形成されなかったベース部材５０の表面は、露出領域５１Ｂとなる。図９を参照して、被覆領域５１Ａと露出領域５１Ｂとの境界が肉盛端部５９である。なお、肉盛溶接は、たとえば溶接電流２３０Ａ、溶接電圧１７Ｖ、硬質粒子の供給量１１０ｇ／ｍｉｎ、ビード余盛高さ４ｍｍの条件で実施することができる。溶接ワイヤとしては、ＪＩＳ規格ＹＧＷ１１を採用してもよい。硬質粒子としては、ＷＣ、Ｗ２Ｃ系の粒子を採用してもよい。 When the welding torch 70 and the hard particle supply nozzle 80 constituting the build-up welding apparatus move relative to the base member 50 in the direction of the arrow α, the position where the molten pool 92 is formed moves sequentially and is formed first. The molten pool 92 that has been solidified becomes a built-up layer 60. The build-up layer 60 includes a mother phase 95 formed by solidifying the molten pool 92 and hard particles 91 dispersed in the mother phase 95. By the above procedure, the overlay layer 60 covering the covering region 51A on the surface of the base member 50 is formed. The surface of the base member 50 where the overlay layer 60 is not formed becomes an exposed region 51B. With reference to FIG. 9, the boundary between the covered region 51 </ b> A and the exposed region 51 </ b> B is the built-up end portion 59. The build-up welding can be performed, for example, under the conditions of a welding current of 230 A, a welding voltage of 17 V, a hard particle supply amount of 110 g / min, and a bead surplus height of 4 mm. JIS standard YGW11 may be adopted as the welding wire. As the hard particles, WC or W 2 C-based particles may be employed.
　次に、工程（Ｓ３０）として熱間鍛造工程が実施される。この工程（Ｓ３０）では、工程（Ｓ２０）において肉盛層６０が形成されたベース部材５０が熱間鍛造される。図９および図３を参照して、肉盛層６０が形成されたベース部材５０が熱間鍛造可能な温度に加熱された上で、所望のツース２０の形状に対応するキャビティを有する金型内に配置され、鍛造される。この熱間鍛造により、肉盛端部５９を含むベース部材５０の領域が加工される。熱間鍛造により、肉盛端部５９は肉盛端部２９となる。熱間鍛造において肉盛端部５９が加工されることにより、肉盛端部２９において、露出領域２５Ｂと肉盛層２７の表面２７Ａとが同一面を構成するツース２０が得られる。肉盛端部２９において、露出領域２５Ｂと肉盛層２７の表面２７Ａとは、熱間鍛造において用いられる金型の表面の肉盛端部５９を加工する領域に対応する同一面を構成する鍛造面となる。肉盛端部２９において、露出領域２５Ｂと肉盛層２７の表面２７Ａとは、鍛造用の金型の形状に対応する同一面を構成する。肉盛端部２９は、鍛造面に含まれる。 Next, a hot forging process is performed as a process (S30). In this step (S30), the base member 50 on which the build-up layer 60 is formed in the step (S20) is hot forged. Referring to FIGS. 9 and 3, the base member 50 on which the build-up layer 60 is formed is heated to a temperature at which hot forging is possible, and the inside of the mold having a cavity corresponding to the shape of the desired tooth 20 is obtained. Placed and forged. By this hot forging, the region of the base member 50 including the built-up end portion 59 is processed. Due to the hot forging, the built-up end portion 59 becomes the built-up end portion 29. By processing the built-up end portion 59 in the hot forging, the tooth 20 in which the exposed region 25B and the surface 27A of the built-up layer 27 form the same surface in the built-up end portion 29 is obtained. In the built-up end portion 29, the exposed region 25B and the surface 27A of the built-up layer 27 are forged to form the same surface corresponding to the region where the built-up end portion 59 of the mold surface used in hot forging is processed. It becomes a surface. In the built-up end portion 29, the exposed region 25B and the surface 27A of the built-up layer 27 constitute the same surface corresponding to the shape of the forging die. The built-up end portion 29 is included in the forged surface.
　図１０および図５を参照して、肉盛層６０が形成されたベース部材５０が熱間鍛造されることにより、肉盛層６０の形成時において肉盛層６０の表面から突出していた硬質粒子９１は、肉盛層６０の内部へと押し込まれる。その結果、ツース２０では、肉盛層表層領域２７Ｂ内に位置する硬質粒子９１は、肉盛層２７の表面２７Ａに接するように配置される（図５参照）。肉盛層表層領域２７Ｂ内に位置する硬質粒子９１の、肉盛層２７の表面２７Ａから露出する領域に対応する中心角θは鋭角（９０°未満）となる。これにより、ツース２０の使用中における硬質粒子９１の脱落が抑制され、ツース２０の耐摩耗性が向上する。 Referring to FIG. 10 and FIG. 5, the hard particles protruding from the surface of the built-up layer 60 when the built-up layer 60 is formed by hot forging the base member 50 on which the built-up layer 60 is formed. 91 is pushed into the built-up layer 60. As a result, in the tooth 20, the hard particles 91 located in the built-up layer surface layer region 27B are arranged so as to contact the surface 27A of the built-up layer 27 (see FIG. 5). The central angle θ corresponding to the region exposed from the surface 27A of the built-up layer 27 of the hard particles 91 located in the built-up layer surface region 27B is an acute angle (less than 90 °). Thereby, dropping of the hard particles 91 during use of the tooth 20 is suppressed, and the wear resistance of the tooth 20 is improved.
　図１０および図６を参照して、肉盛層６０が形成されたベース部材５０が熱間鍛造されることにより、肉盛層６０の形成時において肉盛層６０とベース部材５０との界面付近に位置していた硬質粒子９１の影響により、ツース２０では、肉盛層２７に突出部９９が形成される。突出部９９には、硬質粒子９１の少なくとも一部が進入した状態となる。上記プロセスにより、表面２７Ａに接するように硬質粒子９１が配置された耐摩耗性に優れた肉盛層２７の表層領域と、肉盛層２７のベース部２５からの剥離を抑制する突出部９９とが同時に形成される。 Referring to FIGS. 10 and 6, the base member 50 on which the build-up layer 60 is formed is hot forged so that the vicinity of the interface between the build-up layer 60 and the base member 50 is formed when the build-up layer 60 is formed. Due to the influence of the hard particles 91 located in the protrusion 20, the protrusions 99 are formed in the overlay layer 27 in the tooth 20. At least a part of the hard particles 91 enters the protruding portion 99. By the above process, the surface layer region of the build-up layer 27 excellent in wear resistance in which the hard particles 91 are arranged so as to be in contact with the surface 27A, and the protrusion 99 that suppresses the peeling of the build-up layer 27 from the base portion 25; Are formed simultaneously.
　図７を参照して、次に工程（Ｓ４０）として熱処理工程が実施される。この工程（Ｓ４０）では、工程（Ｓ３０）において熱間鍛造されて得られたツース２０に対して、熱処理が実施される。工程（Ｓ４０）において実施される熱処理は、たとえば焼入および焼戻である。これにより、ツース２０のベース部２５に対し、所望の硬度および靱性を付与することができる。以上の手順により、本実施の形態におけるツース２０が完成する。 Referring to FIG. 7, a heat treatment step is performed as a next step (S40). In this step (S40), heat treatment is performed on the tooth 20 obtained by hot forging in the step (S30). The heat treatment performed in the step (S40) is, for example, quenching and tempering. Thereby, desired hardness and toughness can be imparted to the base portion 25 of the tooth 20. The tooth 20 in the present embodiment is completed by the above procedure.
　なお、上記実施の形態の耐摩耗部品の製造方法において、ベース部材に肉盛層を形成するに際して、肉盛層が形成されるべきベース部材の領域に対応するベース部材の表層部を予め除去してから、すなわちベース部材にアンダーカット部を形成してから肉盛層を形成してもよい。これにより、鍛造時における肉盛層の変形量が抑制され、鍛造後の肉盛層にしわが形成される等の不具合を抑制できる。 In the method for manufacturing a wear-resistant component according to the above embodiment, when forming the build-up layer on the base member, the surface layer portion of the base member corresponding to the region of the base member where the build-up layer is to be formed is removed in advance. In other words, the overlay layer may be formed after the undercut portion is formed on the base member. Thereby, the deformation amount of the built-up layer at the time of forging is suppressed, and problems such as formation of wrinkles on the built-up layer after forging can be suppressed.
　上記実施の形態において説明した製造方法と同様の手順でツース２０を作製し、肉盛層の構造等を確認するとともに、得られたツース２０の粘土への貫入抵抗を確認する実験を行った（実施例）。比較のため、同様の製造方法において、肉盛層形成工程（工程（Ｓ２０））を省略し、熱処理後に肉盛層を肉盛溶接により形成したツースを作製し、同様の実験を行った（比較例）。実施例および比較例において、熱間鍛造に用いた金型は同一形状を有するものである。実験の詳細は以下の通りである。 The tooth 20 was produced in the same procedure as the manufacturing method described in the above embodiment, and the structure of the overlay layer and the like were confirmed, and an experiment was conducted to confirm the penetration resistance of the obtained tooth 20 into the clay ( Example). For comparison, in the same manufacturing method, the overlay layer forming step (step (S20)) was omitted, and a tooth was formed by depositing the overlay layer after heat treatment, and a similar experiment was performed (comparison) Example). In the examples and comparative examples, the molds used for hot forging have the same shape. The details of the experiment are as follows.
　図１１は、実施例のツース２０の断面を示す写真である。図１１を参照して、肉盛端部２９において、露出領域２５Ｂと肉盛層２７の表面２７Ａとは同一面を構成する鍛造面となっている。このことから、上記実施の形態における製造方法により、上記実施の形態におけるツース２０が製造可能であることが確認される。肉盛層２７とベース部２５との間に亀裂は見られず、肉盛層の形成後に熱間鍛造を実施したことによる不具合は確認されない。 FIG. 11 is a photograph showing a cross section of the tooth 20 of the example. Referring to FIG. 11, in the built-up end portion 29, the exposed region 25 </ b> B and the surface 27 </ b> A of the built-up layer 27 are forged surfaces that constitute the same surface. From this, it is confirmed that the tooth 20 in the said embodiment can be manufactured with the manufacturing method in the said embodiment. A crack is not seen between the build-up layer 27 and the base part 25, and the malfunction by having implemented hot forging after formation of the build-up layer is not confirmed.
　図１２は、実施例の肉盛層の表面付近を撮影した光学顕微鏡写真である。図１３は、比較例の肉盛層の表面付近を撮影した光学顕微鏡写真である。図１３に示すように、肉盛溶接により形成され、その後鍛造による加工を受けていない比較例の肉盛層では、硬質粒子９１が肉盛層の表面２７Ａから大きく突出している。図１２を参照して、肉盛層の形成後に鍛造による加工を受けた実施例の肉盛層では、表層領域に位置する硬質粒子９１が、肉盛層（母相９５）に埋め込まれた状態で並んで配置されている。硬質粒子９１が肉盛層２７の表面２７Ａに接するように並んでいる。硬質粒子９１の、肉盛層２７の表面２７Ａから露出する領域に対応する中心角θは鋭角（９０°未満）となっている。これは、肉盛層が鍛造により加工される際に、肉盛層の表面２７Ａから突出していた硬質粒子９１が相対的に硬度の低い母相９５内に押し込まれるためであると考えられる。 FIG. 12 is an optical micrograph of the vicinity of the surface of the overlay layer of the example. FIG. 13 is an optical micrograph of the vicinity of the surface of the overlay layer of the comparative example. As shown in FIG. 13, in the build-up layer of the comparative example that is formed by build-up welding and has not been subjected to processing by forging after that, the hard particles 91 protrude greatly from the surface 27 </ b> A of the build-up layer. Referring to FIG. 12, in the build-up layer of the example that has undergone processing by forging after formation of the build-up layer, hard particles 91 located in the surface layer region are embedded in the build-up layer (parent phase 95). Are arranged side by side. The hard particles 91 are arranged in contact with the surface 27 </ b> A of the built-up layer 27. The central angle θ corresponding to the region of the hard particles 91 exposed from the surface 27A of the built-up layer 27 is an acute angle (less than 90 °). This is considered to be because when the build-up layer is processed by forging, the hard particles 91 protruding from the surface 27A of the build-up layer are pushed into the parent phase 95 having a relatively low hardness.
　図１４は、実施例の肉盛層とベース部との界面付近を撮影した光学顕微鏡写真である。図１５は、比較例の肉盛層とベース部との界面付近を撮影した光学顕微鏡写真である。図１５に示すように、肉盛溶接により肉盛層が形成され、その後肉盛層が鍛造による加工を受けていない比較例では、肉盛層（母相９５）とベース部２５との界面は平坦な状態となっている。図１４を参照して、肉盛層の形成後に鍛造による加工を受けた実施例では、肉盛層（母相９５）とベース部２５との界面を含む領域に、肉盛層（母相９５）がベース部２５に向けて突出する突出部９９が形成されている。この突出部９９には、硬質粒子９１の一部が進入している。突出部９９は、肉盛層が鍛造により加工される際に、ベース部材との界面付近に存在していた硬質粒子９１の影響により形成されたものと考えられる。突出部９９の形成に寄与した硬質粒子９１は、当該突出部９９の内部に、少なくともその一部が進入した状態となる。 FIG. 14 is an optical micrograph of the vicinity of the interface between the build-up layer and the base portion of the example. FIG. 15 is an optical micrograph of the vicinity of the interface between the overlay layer and the base portion of the comparative example. As shown in FIG. 15, in the comparative example in which the build-up layer is formed by build-up welding and the build-up layer is not subjected to processing by forging, the interface between the build-up layer (matrix phase 95) and the base portion 25 is It is in a flat state. Referring to FIG. 14, in the example in which processing by forging was performed after the build-up layer was formed, the build-up layer (matrix 95) was formed in a region including the interface between the build-up layer (matrix 95) and the base portion 25. ) Projecting toward the base portion 25 is formed. A part of the hard particles 91 enters the protruding portion 99. The protrusion 99 is considered to be formed by the influence of the hard particles 91 that existed in the vicinity of the interface with the base member when the build-up layer is processed by forging. The hard particles 91 that have contributed to the formation of the protruding portion 99 are in a state in which at least a part thereof has entered the protruding portion 99.
　次に、ツースの貫入抵抗試験について説明する。図１６は、貫入抵抗試験に供した実施例のツースの外観を撮影した写真である。図１７は、貫入抵抗試験に供した比較例のツースの外観を撮影した写真である。図１６に示すように、肉盛層の形成後に鍛造による加工を受けた実施例では、ツースの表面が平坦な状態となっている。図１７に示すように、肉盛溶接により肉盛層が形成され、その後肉盛層が鍛造による加工を受けていない比較例では、ツースの表面において段差を形成するように肉盛層２７が存在している。図１６および図１７に示すツースを、土砂を想定した油粘土に貫入させ、その際の貫入抵抗を測定する実験を行った。貫入時のツースの変位速度は１ｍｍ／ｓｅｃとし、ツースの先端が深さ５０ｍｍの位置に到達するまで、表面が平坦な油粘土中にツースを貫入させた。 Next, the penetration resistance test for teeth will be explained. FIG. 16 is a photograph of the appearance of the tooth of the example used for the penetration resistance test. FIG. 17 is a photograph of the appearance of the tooth of the comparative example subjected to the penetration resistance test. As shown in FIG. 16, in the Example which received the process by forging after formation of the build-up layer, the surface of a tooth is in the flat state. As shown in FIG. 17, in the comparative example in which the build-up layer is formed by build-up welding and the build-up layer is not subjected to forging processing thereafter, the build-up layer 27 exists so as to form a step on the surface of the tooth. is doing. An experiment was conducted in which the teeth shown in FIGS. 16 and 17 were made to penetrate oil clay assuming earth and sand, and the penetration resistance at that time was measured. The displacement speed of the tooth at the time of penetration was 1 mm / sec, and the tooth was penetrated into oil clay having a flat surface until the tip of the tooth reached a position where the depth was 50 mm.
　図１８は貫入抵抗試験の結果を示す図である。図１８において、実線は実施例、破線は比較例の試験結果に対応する。図１８を参照して、ツースの変位が５０ｍｍに到達した時点における貫入抵抗は、比較例が約０．２５ｋＮであったのに対し、実施例では約０．２１ｋＮとなっている。実施例は比較例に比べて貫入抵抗が約１５％低減されている。このように、本発明の耐摩耗部品である上記実施の形態のツース２０によれば、肉盛層２７の形成に起因したデメリットである貫入抵抗の上昇を抑制できることが確認される。 FIG. 18 shows the results of the penetration resistance test. In FIG. 18, the solid line corresponds to the test result of the example, and the broken line corresponds to the test result of the comparative example. Referring to FIG. 18, the penetration resistance when the displacement of the tooth reaches 50 mm is about 0.25 kN in the comparative example, and is about 0.21 kN in the example. The penetration resistance of the example is reduced by about 15% compared to the comparative example. Thus, according to the tooth 20 of the said embodiment which is an abrasion-resistant component of this invention, it is confirmed that the raise of the penetration resistance which is a demerit resulting from formation of the build-up layer 27 can be suppressed.
　なお、上記実施の形態においては、本発明の耐摩耗部品の一例として作業機械（油圧ショベル）のバケットのツースについて説明したが、本発明の耐摩耗部品はこれに限られず、たとえば作業機械の履帯式足回りを構成するローラ、ブシュ、リンク、シュー、アイドラ、スプロケット（スプロケットティース）などの部品や、コンクリート破砕用の破砕装置の歯などに適用することができる。上記実施の形態では、バケットのツースとして、小型の油圧ショベル用の中実のツースについて説明したが、バケットのアダプタに被せるように取り付けて使用される中、大型油圧ショベル用のツースにも本発明の耐摩耗部品を適用することができる。 In the above embodiment, the tooth of the bucket of the working machine (hydraulic excavator) has been described as an example of the wear-resistant part of the present invention. However, the wear-resistant part of the present invention is not limited to this, for example, the crawler belt of the work machine. It can be applied to components such as rollers, bushes, links, shoes, idlers and sprockets (sprocket teeth) constituting the undercarriage, and teeth of a crushing device for crushing concrete. In the above embodiment, a solid tooth for a small hydraulic excavator has been described as a tooth for a bucket. However, the present invention is also applicable to a tooth for a large excavator while being used so as to cover the adapter of the bucket. Wear-resistant parts can be applied.
　今回開示された実施の形態および実施例はすべての点で例示であって、どのような面からも制限的なものではないと理解されるべきである。本発明の範囲は上記した説明ではなく、請求の範囲によって規定され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 It should be understood that the embodiments and examples disclosed this time are examples in all respects and are not restrictive in any aspect. The scope of the present invention is defined by the scope of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the scope of the claims.
　本発明の耐摩耗部品およびその製造方法は、肉盛層を有する耐摩耗部品およびその製造方法に、特に有利に適用され得る。 The wear-resistant component and the manufacturing method thereof according to the present invention can be particularly advantageously applied to the wear-resistant component having a built-up layer and the manufacturing method.
　１　バケット、１０　本体、１２　開口外周部、２０　ツース、２１　先端、２２　基端、２５　ベース部、２５Ａ　被覆領域、２５Ｂ　露出領域、２７　肉盛層、２７Ａ　表面、２７Ｂ　肉盛層表層領域、２９　肉盛端部、３０　装着部、５０　ベース部材、５１　側面、５１Ａ　被覆領域、５１Ｂ　露出領域、５２　一方の端面、５２Ａ　第１面取り部、５３　他方の端面、５３Ａ　第２面取り部、５９　肉盛端部、６０　肉盛層、７０　溶接トーチ、７１　溶接ノズル、７２　コンタクトチップ、７３　溶接ワイヤ、７４　アーク、８０　硬質粒子供給ノズル、９１　硬質粒子、９２　溶融池、９５　母相、９９　突出部。 1 bucket, 10 body, 12 opening outer periphery, 20 tooth, 21 tip, 22 base end, 25 base part, 25A covering area, 25B exposed area, 27 overlaying layer, 27A surface, 27B overlaying layer surface area, 29 meat Embankment end, 30 mounting portion, 50 base member, 51 side surface, 51A covering region, 51B exposed region, 52 one end surface, 52A first chamfered portion, 53 other end surface, 53A second chamfered portion, 59 built-up end portion , 60 overlay, 70 welding torch, 71 welding nozzle, 72 contact tip, 73 welding wire, 74 arc, 80 hard particle supply nozzle, 91 hard particle, 92 molten pool, 95 parent phase, 99 protrusion.

Claims (10)

  1. 　第１金属からなるベース部と、
    　前記ベース部の表面の一部である被覆領域を覆うように前記ベース部に接触して配置される肉盛層と、を備え、
    　前記ベース部の表面の、前記被覆領域と前記被覆領域以外の領域である露出領域との境界である肉盛端部において、前記露出領域と前記肉盛層の表面とは同一面を構成する鍛造面となっている、耐摩耗部品。     A base portion made of a first metal;
    A built-up layer disposed in contact with the base portion so as to cover a covering region that is a part of the surface of the base portion,
    Forging in which the exposed region and the surface of the built-up layer form the same surface at the built-up end portion of the surface of the base portion that is a boundary between the covered region and the exposed region other than the covered region Wear-resistant parts on the surface.
  2. 　前記肉盛層は、
    　第２金属からなる母相と、
    　前記母相中に分散する硬質粒子と、を含む、請求項１に記載の耐摩耗部品。     The overlay layer is
    A matrix composed of a second metal;
    The wear-resistant component according to claim 1, comprising hard particles dispersed in the matrix.
  3. 　前記肉盛層の前記表面から前記硬質粒子の平均粒径以内の領域である肉盛層表層領域内に位置する前記硬質粒子は、前記肉盛層に埋め込まれた状態で並んで配置される、請求項２に記載の耐摩耗部品。 The hard particles located in the surface layer region of the built-up layer, which is a region within the average particle diameter of the hard particles from the surface of the build-up layer, are arranged side by side in a state embedded in the build-up layer, The wear-resistant component according to claim 2.
  4. 　前記肉盛層表層領域内に位置する前記硬質粒子は、前記肉盛層の前記表面に接するように配置される、請求項３に記載の耐摩耗部品。 The wear-resistant part according to claim 3, wherein the hard particles located in the surface layer region of the buildup layer are disposed so as to contact the surface of the buildup layer.
  5. 　前記肉盛層表層領域内に位置する前記硬質粒子の、前記肉盛層の前記表面から露出する領域に対応する中心角は鋭角である、請求項３に記載の耐摩耗部品。 The wear-resistant component according to claim 3, wherein a central angle of the hard particles located in the surface layer region of the buildup layer corresponding to a region exposed from the surface of the buildup layer is an acute angle.
  6. 　前記肉盛層は、前記肉盛層と前記ベース部との界面を含む領域において、前記ベース部に向けて突出する突出部を含む、請求項２～５のいずれか１項に記載の耐摩耗部品。 The wear resistance according to any one of claims 2 to 5, wherein the build-up layer includes a protruding portion that protrudes toward the base portion in a region including an interface between the build-up layer and the base portion. parts.
  7. 　前記突出部には、前記硬質粒子の少なくとも一部が進入している、請求項６に記載の耐摩耗部品。 The wear-resistant component according to claim 6, wherein at least a part of the hard particles have entered the protrusion.
  8. 　第１金属からなるベース部材を準備する工程と、
    　前記ベース部材の表面の一部である被覆領域に接触して前記被覆領域を覆うように、肉盛層を形成する工程と、
    　前記ベース部材の表面の、前記被覆領域と前記被覆領域以外の領域である露出領域との境界である肉盛端部が加工されるように、前記肉盛層が形成された前記ベース部材を鍛造する工程と、を備える、耐摩耗部品の製造方法。     Preparing a base member made of a first metal;
    Forming a build-up layer so as to cover the covering region in contact with the covering region that is a part of the surface of the base member;
    The base member on which the build-up layer is formed is forged so that a built-up end portion that is a boundary between the cover region and an exposed region other than the cover region on the surface of the base member is processed. A method of manufacturing a wear-resistant component.
  9. 　前記肉盛層が形成された前記ベース部材を鍛造する工程では、前記肉盛層が形成された前記ベース部材が熱間鍛造される、請求項８に記載の耐摩耗部品の製造方法。 The method for manufacturing a wear-resistant part according to claim 8, wherein in the step of forging the base member on which the build-up layer is formed, the base member on which the build-up layer is formed is hot forged.
  10. 　前記肉盛層を形成する工程では、第２金属からなる母相と、前記母相中に分散する硬質粒子と、を含む前記肉盛層が形成される、請求項８または９に記載の耐摩耗部品の製造方法。 The build-up resistance according to claim 8 or 9, wherein, in the step of forming the build-up layer, the build-up layer including a parent phase made of a second metal and hard particles dispersed in the parent phase is formed. A method for manufacturing worn parts.
PCT/JP2014/080538 2014-11-18 2014-11-18 Wear-resistant component and production method for same WO2016079811A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018053678A (en) * 2016-09-30 2018-04-05 株式会社小松製作所 Sediment wear-resistant component and method for producing the same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6557679B2 (en) * 2014-11-18 2019-08-07 株式会社小松製作所 Sprocket and manufacturing method thereof
US10730129B2 (en) * 2014-11-18 2020-08-04 Komatsu Ltd. Machine component and method for producing the same
JPWO2021205969A1 (en) * 2020-04-09 2021-10-14

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0323025A (en) * 1989-06-20 1991-01-31 Komatsu Ltd Method for burying hard fine particle in metal
JPH0577042A (en) * 1991-09-17 1993-03-30 Isuzu Motors Ltd Method for reforming surface of cast iron parts
JPH0847774A (en) * 1994-08-02 1996-02-20 Komatsu Ltd Method for build up welding wear resistant layer, and wear resistant composite material using the method
JP2013046928A (en) * 2011-07-25 2013-03-07 Daido Steel Co Ltd Method of manufacturing exhaust valve for vessel engine

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5852272A (en) 1994-08-02 1998-12-22 Komatsu Ltd. Wear-resistant overlay forming method and wear-resistant composite members
US6118098A (en) 1997-10-10 2000-09-12 Siemens Westinghouse Power Corporation Turbine rotor modernization and repair method
JP4901324B2 (en) 2006-06-20 2012-03-21 株式会社小松製作所 Method of forming hardfacing layer
US9121237B2 (en) * 2011-07-28 2015-09-01 Baker Hughes Incorporated Methods of coating wellbore tools and components having such coatings
EP2740908B1 (en) * 2012-06-14 2016-10-26 Nittan Valve Co., Ltd. Method of forming poppet valve faces and poppet valves having faces formed by this method
CN103706921B (en) * 2013-12-23 2015-08-12 鞍钢实业集团冶金机械有限公司 Hot-rolling finishing mill backing roll build-up welding repair method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0323025A (en) * 1989-06-20 1991-01-31 Komatsu Ltd Method for burying hard fine particle in metal
JPH0577042A (en) * 1991-09-17 1993-03-30 Isuzu Motors Ltd Method for reforming surface of cast iron parts
JPH0847774A (en) * 1994-08-02 1996-02-20 Komatsu Ltd Method for build up welding wear resistant layer, and wear resistant composite material using the method
JP2013046928A (en) * 2011-07-25 2013-03-07 Daido Steel Co Ltd Method of manufacturing exhaust valve for vessel engine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018053678A (en) * 2016-09-30 2018-04-05 株式会社小松製作所 Sediment wear-resistant component and method for producing the same
WO2018062127A1 (en) * 2016-09-30 2018-04-05 株式会社小松製作所 Part resistant to erosion wear and manufacturing method for same
AU2017338154B2 (en) * 2016-09-30 2020-02-06 Komatsu Ltd. Part resistant to erosion wear and manufacturing method for same

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